The department reviews insurance carriers' proposals to determine if rates are "unreasonable," according to a statement Monday.

In past years, the department has successfully negotiated lower increases with carriers to avoid labeling them "unreasonable."

Final rates will be publicly available by mid-September or early October.

"I am deeply disappointed and frustrated to share these rates," department director Dean Cameron said in the statement. "I understand how difficult it will be for Idahoans to afford reasonable coverage, especially those without a subsidy."

In particular, proposed increases to silver level plans on the exchange are significantly higher this year, the department said.

That's due to the "potential refusal by the federal government to fund the Cost Share Reduction (CSR) mechanism," according to the statement. "The CSR requires insurance carriers selling plans through Your Health Idaho to lower deductibles and out-of-pocket maximums on Silver plans for enrollees who earn below 250% of the federal poverty level."

For 2018, carrier participation across Idaho also dropped due to BridgeSpan Health Company withdrawing and a reduction in served by SelectHealth in eastern Idaho.